The light

It is one of the most important elements because the plants can't develop in a proper way when is not enough light, or if they still grow there are many chances not to bloom and bear fruits as you like. If you want a garden and have the possibility to decide where it should be, choose a place as brighter as can be because most plants (vegetables) need 6-8 hours of bright light per day. When you are the lucky owner of a such place you have big chances to grow successfully bright light loving plants: tomatoes, peppers, eggplants, melons, corn etc. This doesn’t mean that those with no bright place are condemned. In some cases too much light can damage. The water evaporates too fast, the leaves and flowers wilt or burn. Plus there are plants which can’t stand the bright light (Begonia).

Even if your garden is semi-shaded this doesn't mean you can't grow bright light loving plants. Maybe they don't produce at full potential, but there are still chances to grow and bear fruits. Nobody can stop you to experiment and try. There are many cases when gardeners obtained tomatoes and peppers from partial shade gardens. The point is that it must not be total dark. (Even on the grounds with full shadow, grow plants like: ferns, ivy, mushrooms etc, because the plants have a big capacity to adapt.)

When your place is not sunny all the time you have to take some measures before you start the work. Note how many hours of sun per day are on plot, which are the sunny areas, at which moments of day are lighted and for how long. You can take some pictures of the garden in different moments of the day so you can work better on the project.

You can grow bright light loving plants (tomatoes, peppers) on the areas which are lighted more hours then others. In the areas where the light is for a limited time or is not so bright you can grow plants which tolerate partial shade (lettuce, spinach, parsley). Generally the plants need a lot of light to make flowers, fruits and seeds, but for stalks and leaves they can manage even with less light. So, if you want to grow vegetables for fruits (tomatoes) the place needs a lot of light, but if you want vegetable for leaves (lettuce) it's ok with less light too.

Here are two lists with few light loving or shade tolerating plants.

Bright light loving plants

Peppers

Cauliflower

Watermelon

Broccoli

Chrysanthemums

Marjoram

Basil

Dahlia

Oregano

Potatoes

Pumpkins (squashes, zucchini)

Purslane

Cucumbers

Beans

Tomatoes

Zinnia

Calendula

Rosemary

Onion

Lavender

Eggplants

Partial shade tolerating plants

Crocus

Sorrel

Lovage

Chervil

Pea

Lettuce

Columbine

Mint

Beat

Coriander

Monarda

Spinach

Fuchsia

Carrots

Celery

Impatiens

Forget-me-not

Thyme

Bleeding heart

Parsley

Cabbage

You can take into account the fact that in the morning the sun light is much cooler than in the afternoon. So if some areas are sunny just in the morning than you can grow there plants which don't tolerate strong light. If there are some areas in the garden lighted just in the afternoon you can grow on them plants which love hot bright light.

You must observe what is the cause of the shadow in garden (trees, bushes, walls, neighbouring buildings) and take some measures if it's possible (cut the bushes, some tree branches). Even when you can't move away or pull down a building, you can do something else to increase the light quantity. For example you can paint a trouble wall in white or other pale color, put some white or pale colored stones around, mirrors etc.

Grow the small plants in front of the tall ones thus they not shadow each other and have much light. So if you are in the north hemisphere the tallest plants will be on the north side of the garden and the small ones on the south side.

Also you can grow some plants in pots (container garden) and move them from a sunny area to another as the sun travels the sky.